This task of changing the oil in internal combustion engines is periodically required to obtain acceptable performance and engine life. Many industrial and aircraft internal engines are equipped with oil crankcase drainage systems to facilitate this required maintenance. However, many internal combustion engine crankcase drain ports, especially automobile and boat engines, come equipped only with plugs. In order to drain oil, a funnel, oil receptacle and wrench are typically used in conjunction with disposable rags to clean the splash that inevitably occurs. In addition, the drained oil must then be typically transferred again for disposal or recycling. Frequent use may also result in stripped threads and leakage at the drainplug.
Because of the nature of this maintenance chore, many consumers have oil changes done at a service station or garage. The need to place automobile, get the proper funnel and tools, obtain and place oil receptacle, remove plug, clean plug, clean funnel, clean oil receptacle, clean tools, transfer oil for disposal/recyling, risk of spills, risk of stripped threads, replacement of tools and under engine position deters many consumers from accomplishing these periodic chores.
Many previous attempts have been made to improve and simplify this task. U.S. Pat. No. 3,727,638 represents one type of simple system. The drain plug is replaced by stem draining valve attached to a hose and receptacle. The valve is closed during engine operation and opened after connecting hose and receptacle. A dust cap was provided to protect the exposed hose fitting and the valve stem during engine operation. Installation and operation of the valve required tools, specifically wrenches acting on stem or tubular valve body.
This type of simple drain system eliminates many problems with the conventional automobile crankcase draining efforts previously described. However, the hose fitting dust cap removal added an operation. The exposed position of valve stem fitting also interfered with ground clearance on vehicle. The stem was susceptible to loosening and damage by road debris. In addition, two tools were now required for operation, one wrench to retain valve body and a second to operate the valve stem. The drained oil receptacle was typically a bag or expended new oil container. Variations on this basic approach include hose fittings which opened valve when attached, (U.S. Pat. No. 4,269,237) sophisticated latched valves (U.S. Pat. Nos. 4,078,763 and 3,874,478) or rupture diaphragms (U.S. Pat. No. 4,373,561). Variations have solved some of the noted problems, but add new problems of cost and added complexity.
A second approach to this draining task is remote control drain valves. U. S. Pat. No. 3,650,352 is typical of this approach which includes a cable, knob, cable and knob support, latch and cable operated valve.
Although this approach allows the drain to be actuated remotely, it still requires the connection and/or placement of a used oil receptacle proximate to the drain port. Cables, supports, seals and valve also adds significantly to cost and complexity, and requires significant space on engine for mounting remote valves, cable supports, and knob/latch supports. Variations include combined drain hose and cable runs (U.S. Pat. No. 3,871,483) or placing valve/plug at the end of a permanently attached drain hose (U.S. Pat. Nos. 4,033,432 and 3,103,947).
Still another approach is to combine a disposable receptacle with the drain valve. U.S. Pat. No. 4,386,639 is an example. This approach typically includes a spring-loaded valve, a disposable receptacle, which includes a fitting which attaches to/and opens valve. Variations include a disk valve and snap fitting (U.S. Pat. No. 4,530,421), and a drain pan/receptacle combination (U.S. Pat. No. 4,054,184). The special fittings required by this approach add significantly to the cost and complexity, since receptacle fitting is disposed of at each oil change. Special fittings on vehicles also generally require protective covers when not in use.
Other approaches have included complex pumping modules to evacuate old oil and dispense new oil (U.S. Pat. No. 3,867,999), drain plug removal mechanisms with drainage systems (U.S. Pat. No. 4,592,448) or with receptacle (U.S. Pat. No. 4,533,042), and disposable receptacles which originally contained new oil and, when empty, receive drained oil (U.S. Pat. No. 4,098,398).
All of these approaches have found limited application. This appears to be a result of excess cost and/or remaining problems. All approaches to date have (1) required tools or permanent attachments to install and/or operate the drainage system, and (2) require significant additional engine space and/or impair road clearance.
Critical to this application is the discharge valve replacing the drain plug. Most prior applications use stem discharge designs, but these all require more space, possibly impacting road clearances. Bottom or through stem discharges are also exposed to road debris.